Stepper motor looses some steps

Acceleration, jerk and speed settings in the firmware might be too high. To confirm this print pieces with long thin parts having smooth movements. Infill with honeycomb make lots of movement.

Current in the stepper motor is too low.

Friction in the mechanical system is too low.

Nozzle has collision with previous layer due to too much material printed. Or if happens on the first layers then the Z axis is not well calibrated.

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